分步注册方式 编写驱动

作业：通过分步注册方式，编写LED灯驱动：（驱动文件mycdev.c 测试文件test.c 头文件head.h)

mycdev.c

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/io.h>
#include <linux/device.h>
#include <linux/cdev.h>
#include <linux/slab.h>
#include "head.h"
struct cdev *cdev;
unsigned int major=0;
unsigned int minor=0;
dev_t devno;
int major;
char kbuf[128] = {0};
gpio_t *vir_led1;
gpio_t *vir_led2;
gpio_t *vir_led3;
unsigned int *vir_rcc;
struct class *cls;
struct device *dev;
int mycdev_open(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}
long mycdev_ioctl(struct file *file,unsigned int cmd, unsigned long arg)
{
    int which;
    int ret = copy_from_user(&which,(unsigned int *)arg,4);
    if(ret)
    {
        printk("copy_from_user err\n");
        return ret;
    }
    switch (cmd)
    {
        case LED_ON://which LED is turned on
        switch(which)
        {
            case 1: //LED1
            vir_led1->ODR |= (0x1 << 10);
            break;
            case 2: //LED2
            vir_led2->ODR |= (0x1 << 10);
            break;
            case 3: //LED3
            vir_led3->ODR |= (0x1 << 8);
            break;
        }
        break;
        case LED_OFF: //which LED is turned off
        switch (which)
        {
            case 1:
            vir_led1->ODR &= (~(0x1 << 10));
            break;
             case 2:
            vir_led2->ODR &= (~(0X1 << 10));
            break;
            case 3:
            vir_led3->ODR &= (~(0X1 << 8));
            break;
        }
        break;
        return 0;
    }
 
}
int all_leds_init(void)
{
    vir_led1 = ioremap(PHY_LED1_ADDR, sizeof(gpio_t));
    if (vir_led1 == NULL)
    {
        printk("ioremap filed：%d\n", __LINE__);
        return -ENOMEM;
    }
    vir_led2 = ioremap(PHY_LED2_ADDR, sizeof(gpio_t));
    if (vir_led2 == NULL)
    {
        printk("ioremap filed：%d\n", __LINE__);
        return -ENOMEM;
    }
    vir_led3 = vir_led1;
    vir_rcc = ioremap(PHY_RCC_ADDR, 4);
    if (vir_rcc == NULL)
    {
        printk("ioremap filed：%d\n", __LINE__);
        return -ENOMEM;
    }
    printk("ioremap success\n");

    // init regestors
    
    (*vir_rcc) |= (3 << 4);

    vir_led1->MODER &= (~(3 << 20));
    vir_led1->MODER |= (1 << 20);
    vir_led1->ODR &= (~(1 << 10));
 
    vir_led2->MODER &= (~(3 << 20));
    vir_led2->MODER |= (1 << 20);
 
    vir_led1->MODER &= (~(3 << 16));
    vir_led1->MODER |= (1 << 16);
    vir_led1->ODR &= (~(1 << 8));
    printk("init regestors success\n");
 
    return 0;
} 
ssize_t mycdev_read(struct file *file, char  *ubuf, size_t size, loff_t *lof)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    int ret;
    ret=copy_to_user(ubuf,kbuf,size);
    if(ret)
    {
        printk("copy_to_user filad\n");
        return ret;
    }
    return 0;
}
 
int mycdev_close(struct inode *inode, struct file *file)
{
    printk("%s:%s:%d\n",__FILE__,__func__,__LINE__);
    return 0;
}

struct file_operations fops = {
    .open=mycdev_open,
    .read=mycdev_read,
    .write=mycdev_write,
    .release=mycdev_close,
};
 
static int __init mycdev_init(void)
{
    int ret;
    //cdev allocate space
    cdev=cdev_alloc();
    if(cdev==NULL)
    {
        printk("cdev allocate space failed\n");
        ret=-EFAULT;
        goto OUT1;
    }
    printk("cdev allocate space success\n");
    cdev_init(cdev,&fops);
    if(major>0)
    {
        ret=register_chrdev_region(MKDEV(major,minor),3,"mycdev");
        if(ret)
        {
            printk("apply for cdev Number failed\n");
            goto OUT2;
        }
    }
    else
    {
        ret=alloc_chrdev_region(&devno,minor,3,"mycdev");
        if(ret)
        {
            printk("apply for cdev Number failed\n");
            goto OUT2;
        }
        minor=MINOR(devno);//minor of cdev Number
        major=MAJOR(devno);//major of cdev Number
        
    }
    printk("cdev Number:major=%d\n", major);
    printk("apply for cdev Number success\n");
    ret=cdev_add(cdev,MKDEV(major,minor),3);
    if(ret)
    {
        printk("regest cdev failed\n");
       goto OUT3;
    }
    printk("regest cdev sucess\n");
    cls=class_create(THIS_MODULE,"mycdev");
    if(IS_ERR(cls))
    {
        printk("submit catalog list failed\n");
        ret=-PTR_ERR(cls);
        goto OUT4;
    }
    printk("submit catalog list success\n");
    int i;
    for(i=0;i<3;i++)
    {
        dev=device_create(cls,NULL,MKDEV(major,i),NULL,"mycdev%d",i);
        if(IS_ERR(dev))
        {
            printk("submit cdev inod failed\n");
            ret=-PTR_ERR(dev);
            goto OUT5;
        }
    }
    printk("submit cdev inod success\n");
    all_leds_init();
    return 0;
OUT5:
    for(--i;i>=0;i--)
    {
        device_destroy(cls,MKDEV(major,i));
    }
    class_destroy(cls);
OUT4:
    cdev_del(cdev);
OUT3:
    unregister_chrdev_region(MKDEV(major,minor),3);
OUT2:
    kfree(cdev);
OUT1:
    return ret;
}
 
static void __exit mycdev_exit(void)
{
    iounmap(vir_led1);
    iounmap(vir_led2);
    iounmap(vir_rcc);
    int i;
    for(i=0;i<3;i++)
    {
        device_destroy(cls,MKDEV(major,i));
    }
    class_destroy(cls);
    cdev_del(cdev);
    unregister_chrdev_region(MKDEV(major,minor),3);
    kfree(cdev);
}
module_init(mycdev_init);
module_exit(mycdev_exit);
MODULE_LICENSE("GPL");

test.c

#include<stdlib.h>
#include<stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include<unistd.h>
#include<string.h>
#include<sys/ioctl.h>
#include"head.h"
 
int main(int argc, char const *argv[])
{
    char buf[128]={0};
    int a,b;
    int fd=open("/dev/mycdev0",O_RDWR);
    if(fd<0)
    {
        printf("open cdev failed\n");
        exit(-1);
    }
    while(1)
    {
        printf("turn on or turn off：1（on）0（off)>）");
        scanf("%d",&a);
        printf("select the LED：1（LED1） 2(LED2) 3(LED3)>");
        scanf("%d",&b);
        switch(a)
        {
            case 1:
                ioctl(fd,LED_ON,&b);
                break;
            case 0:
                ioctl(fd,LED_OFF,&b);
                break;
        }
    }   
    close(fd);
    return 0;
}

head.h

#ifndef __HEAD_H__
#define __HEAD_H__ 
typedef struct{
    unsigned int MODER;
    unsigned int OTYPER;
    unsigned int OSPEEDR;
    unsigned int PUPDR;
    unsigned int IDR;
    unsigned int ODR;
}gpio_t;
#define PHY_LED1_ADDR 0X50006000
#define PHY_LED2_ADDR    0X50007000
#define PHY_LED3_ADDR 0X50006000
#define PHY_RCC_ADDR    0X50000A28
#define LED_ON _IOW('l',1,int)
#define LED_OFF _IOW('l',0,int)
#endif